This invention relates to a fiberglass reinforced plastic damping material and a manufacturing process therefor, and more particularly to an improved damping panel and method of manufacturing it which incorporates as one of the materials a fiberglass reinforced plastic.
There are many instances where it is desirable to provide a panel in a construction that has damping characteristics so as to reduce noise and vibration transmission through the panel. For example, these panels are frequently employed in watercraft hull configurations for dampening the sounds and vibration of the engine and/or propeller or other propulsion device from the occupants of the watercraft.
Normally, the way such damping plates are formed is to lay up or otherwise form a fiberglass reinforced plastic base plate and to affix to that base plate a damping plate having a cushioning property such as rubber or a plastic having rubber-like characteristics. Frequently, it is also desirable if not necessary to provide another retention panel on the side of the damping panel opposite to that attached to the base plate for appearance, structural and other reasons. Such sandwich-type constructions, however, have certain disadvantages.
That is, with the previously proposed structures, the cushioning layer must have a thickness equal to or greater than both the base plate and the facing plate. As a result, weight and volume increase which is not at all desirable.
It is, therefore, a principal object of this invention to provide an improved damping plate material having a light weight, the necessary structural properties and also good damping properties.
It is a further object of this invention to provide an improved fiberglass reinforced plastic panel having cushioning properties and still of light weight and good damping characteristics.
The construction of damping panels of the type described normally consists of forming the base plate and then bonding the cushioning plate to the base plate by means of an adhesive or the like. However, these panels have relatively large surface areas and it is difficult to ensure that the adhesive forms a complete bond between the base plate and the damping plate. Where a further plate is positioned on the opposite side of the damping plate from the base plate, then the problems of bonding becomes significantly increased.
If the surfaces are not completely secured to each other throughout their entire surface, then there will be weak parts occur which can cause separation of the damping plate and not only a decrease in strength, but also a decrease in the damping performance.
It is, therefore, a still further object of this invention to provide an improved method of manufacturing a damping panel.
It is a further object of this invention to provide an improved manufacturing process for damping panels that will ensure complete adhesion of the damping material to the base plate while simplifying the manufacturing process.